A Rub-On Tattoo for Diabetics Could Mean the End of Finger Pricking

Pricking your finger for a blood glucose test will never, ever be fun. Thankfully, scientists have been hard at work on a bloodless and needle-less alternative: a rub-on temporary tattoo that, as weird as it sounds, sucks glucose gently through the surface of the skin.

The thin, flexible device created by nano engineers at the University of California, San Diego (UCSD) is based on the much bulkier GlucoWatch, a now-discontinued wristband that worked through the same glucose-sucking principal.

But the electric current GlucoWatch used to attract glucose to the surface of the skin was too high and wearers were not keen on the discomfort. This temporary tattoo gets around the problem by using a gentler, but still effective, current. It then detects glucose through an enzyme that breaks glucose down into oxygen and hydrogen peroxide. The amount of hydrogen peroxide is a proxy for blood glocal levels.

Now, if you follow the glucose tattoo space closely, you might know that a permanent glucose-sensing tattoo has been floated as an idea for a while. But this is a different type of device entirely. For one, it's not an actual tattoo that involves needles driving glucose-sensing ink into the skin. And for two, it's already been tested in humans. A proof-of-concept study published in Analytical Chemistry found it accurate at measuring blood sugar levels in seven healthy volunteers.

Of course, there's still plenty of work to be done to make it into a device people can use at home over the long term. But a bloodless blood-sugar test will certainly be welcome.